Half-tone-printing plate.



'No. 844,968. PATENTED.FEB.19,1907.

. L. 1?. SMITH.

HALF TONE PRINTING PLATE.

APPLIQATION FILED 00T.17. 1906.

0 WM 5 F W L.

' ATTORNEYS Printing UNITED srArns PATENT, oFF oE.

LEVI FRANKLIN SMITH, OF EL PASO, ILLINOIS.

HALF-TONE-PRINTING PLATE.

Specification of Letters Patent.

Patented Feb. 19, 1907.

Application filed October 17, 1906. Serial No. 339.353.

\ specification.

My invention relates to the production of photographichalf-tone-printing plates; and it has for its object the cheap butsuccessful making of half-tone plates without any expensive apparatus.

I employ a thin flexible sheet of copper that will conform to an unevensurface of glass in the printing-frame without danger of breaking thenegative under the extreme pressure which is employed to bring thenegative and copper into absolute and perfect contact. This enables meto use dry plates which are coated on common glass and does away withthe expensive and troublesome wet-plate outfit and chemicals. These thinflexible copper plates only cost about onethird of the heavy rigidcopper plates, are easily trimmed by a pair of shears like a piece ofpaper, and by my construction of mounting avoids the necessity of arouting-machine and other expensive apparatus.

My invention consists in the novel construction and arrangement of theprintingplate which I will now proceed to describe with reference to thedrawings, in which- Figure 1 is a perspective view of a block on whichthe half-tone plate is to be mounted. Fig. 2 is a perspective view ofthe block with the half-tone copper plate finished and appliedpermanently to theblock. Fig. 3 is a perspective view showing arectangular form of block; and Fig. 4. is a detail view showing the thincopper sheet which is to be mounted on the block, Fig. 3.

Referrin to Fig. 1, A represents a Wooden block which is roughly shapedto receive an oval half-tone plate. It is formed on four sides withbeveled notches a, running out to the face of the block and of greatestdepth at the face. In these notches are tacked closelyfitting copperclips 0, whose upper edges are deflected inwardly and curved to the ovalwhich is to characterize the plate and which upper edges extend up toand terminate flush with the upper face of the block. On the face of theblock A is laid flat the very 1 thin plate B, bearing the half-toneetching. The edges of the plate touch the upper edges of the clip-platesU, and, as seen in Fig. 2, a

l filling of solder is then applied to the clip and plate which holdsthe plate flat upon the block and firmly connects 1t thereto. 1f theblock be rectangular, as in Fig. 3, the clip' plates 0 may extendentirely across the ends of the block, and the plate 15 is soldered atits ends thereto and is held along the middle of the sides by a notchand clip-plate a similar to that employed in Fig. 1.

The half-tone plates B and B are made of very thin copper, so thin as tobe flexible and adjust themselves to the irregularities of the glassnegative in transferring. Two very important advantages are thussecured. ln

l the first place, only about one-third of the copper is required for ahalf-tone plate, and, secondly, the flexible copper plate in adjustingitself to the glass negatives makes a close fit thereto Without risk ofbreaking the negative in the press and permits dry plates made of commonglass to' be employed in making half-tones and does away with theexpensive outfit of apparatus usually employed with the wet-platerocess.

Although t e copper printing-plate is so very thin, by mounting it on asmooth fiat block and securing its edges by the soldered clips a flatand perfect printing-plane is obtained, and there is no need for routingout a thick plate and securing it by tacks on its face driven in therouted-out depression. Furthermore, the half-tone-printing face can bemade the full size of the printing-block.

Although described for half-tone work, it is obvious that line-etchingin zinc, brass, or other metals may be made as thin plates and mountedin the same way. I would also state that my method of connecting thefaceplate to the back is applicable to all kinds of printing-plates,whether engraved or chemically etched, whether made of thin and flexibleplates or thick and rigid plates, whether of a flat plane surface or acurved plane surface, and whether having a wooden backing or a metalbacking.

I claim 1. An engraved printing-plate combined with a wooden back, andmetal side clips secured to the wood and soldered to the edges of theprinting-plate.

engraved printing-plate combined with a Wooden back having bevelednotches, notches along its edges, and metal clips se- [0 and metal clipssecured Within these notches cured in the beveled notches with theirupand soldered to the printing-plate. per edges extending to theprinting-plate and 3. 1Aihal'l'T-tone pgiate gonllposed of a fllexiblesoldered thereto. meta ace, a WOO en aci, and meta clips 1 secured tothe sides of the block, and soldered LEVI FRANKLIN to the marginal edgesof the'printing-plate. Witnesses:

4. A half-tone plate composed of a flexible L. K. EvANs,

metal face, a Wooden back having beveled R. A. TAYLOR.

